Powertrain, generic · Transmission

P07BB Transmission Park Position Sensor/Switch B Circuit Performance/Low

Check engine lightOn
EmissionsNot relevant
Drive cycleRequired
Limp modePossible

With electronic gear selection the park position sensor/switch reports the park request or position. On GM's shift-by-wire selectors (2017 LaCrosse, XT4/XT5, Bolt EV, later SUVs and pickups) it is the P button, read by two redundant analog sensors A and B with separate 'released' and 'pressed' voltage zones. P07BB means sensor B reads in the band between its 'released' and 'pressed' zones (53.2–73.7 % of 5 V, ICCM 45–58 %), checked only when P07B9/P07BA are not set, after two trips. GM's 2017 bulletin also lists it for a knob not fully seated or a connector not latched. No other manufacturer is documented.

Likely causes

P button sensor faulty or worn
Knob not seated, button sticking
Contact resistance in the connector
Module software

Symptoms

  • Check engine light, 'service transmission' or 'unable to shift' message
  • Park cannot be selected by button, or the car will not shift out of P
  • P button illumination off

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–600
Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

park position sensorelectronic range selectorsensor wiringtransmission control module

Related codes

P07BCP07B9P07BAP07BDP07BE

References: gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com, static.nhtsa.gov.